Sheet forming and stacking apparatus



June 26, 1956 J. R. HAWKINS 2,751,981

' SHEET FORMING AND STACKING APPARATUS Filed May 31, 1951 2 Sheets-Sheet 1 &

INVENTOR.

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June 26, 1956 J. R. HAWKINS SHEET FORMING AND STACKING APPARATUS Filed May 31, 1951 2 Sheets-Sheet 2 & IN VEN TOR.

United States Fatent SHEET FOG AND STACKING APPARATUS James R. Hawkins, Deerfield, Ohio, assignor to Armour and Company, Chicago, 111., a corporation of Illinois Application May 31, 1951, Serial No. 229,073

2 Claims. (Cl. 164-68) This invention relates to a sheet forming and stacking machine. The invention is particularly useful in the treating of surface'coated abrasive webs for forming them into sheets and stacking the sheets for packaging. The invention, however, is also applicable to other sheet material.

In the forming of sandpaper and other abrasive sheets and other coated and uncoated sheets, it is common to cut the sheets above a conveyor and to carry the sheets upon the conveyor to a point where the sheets are to be packaged. Unfortunately, sheets of different characteristics, types of coating, etc., fall into different positions upon the conveyor, sometimes upside down and sometimes right side up, and often with considerable overlapping of the edges of the sheets. This is particularly true where a single wide web is slit and the slit web portions then cut transversely to form a plurality of stacks of sheets. The abrasive-equipped paper forms extremely sturdy interlocks and it is diflicult to separate the sheets. Further, considerable time is required in uprighting the sheets which are wrong side down and in assembling the sheets into neat piles for packaging. Considerable labor is required in forming the stacks evenly and with the right number in each stack. There has long been a need for mechanism which would accurately place the sheets in stacks upon conveyors, separating the stacks neatly from each other and forming the stacks automatically with the correct number of sheets in each stack.

An object of the present invention is to overcome the difficulties set out above and to provide mechanism satisfying the need described. A further object is to provide means for causing the severed sheets to fall always right side up in neat piles, while automatically separating the stacks or piles and advancing each pile after it has received the proper number of sheets therein. A further object is to provide adjustable means for elevating a conveyor portion to cause sheets having certain characteristics on falling to be presented in proper order within a stack. A still further object is to provide a conveyor structure which separates the stacks as the stacks are advanced so that the separated stacks may be readily packaged. Yet another object is to provide means for advancing the conveyor means after a predetermined number of sheets have fallen into the several stacks, etc. Other specific objects and advantages will appear as the specification proceeds.

The invention is shown in an illustrative embodiment, by the accompanying drawings, in which Figure 1 is a schematic view in side elevation showing apparatus embodying my invention; Fig. 2, a broken top plan view; Fig. 3, a side view in elevation of the conveyor mechanism adapted to receive the severed sheets; Fig. 4, a top plan View of the conveyor structure shown in Fig. 3; Fig. 5, an enlarged detail and broken end view showing the overlapping edge portions of sheet stacks carried by separate belts; and Fig. 6, a view similar to Fig. 5 but showing the separation of the stacks as the conveyor belts diverge.

2,751,981 Patented June 26, 1956 In the illustration given, 10 designates a roll of sandpaper or other web material. From this source, the web 11 from roll 10 passes under the guide roller 12 and over the guide bar 13 and thence over a roller 14. The web 11 is then cut into four web portions 11a by the slitters 15, as shown more clearly in Fig. 2. The slitted web portions 11a pass between the rubber rollers 16 and thence over an apron support 17 to a knife edge support 18. A rotary knife mechanism 19 is rotated at great speed to sever the portions 11a into sheets 11b.

The sheets 11b fall upon a conveyor which is designated in its entirety by the letter A. The conveyor A is provided with a frame 20 having a rear portion 21 pivoted at its forward end and movable freely at its rear end. The rear end of frame 21 is adjustably supported by the rack bar 22, the rack of which engages a gear 23 mounted in the frame portion 24. The gear shaft 25 is provided with a handle (not shown) for the rotating of the shaft and the movement of the gear for raising or lowering the rack bar 22.

Mounted within the pivotally-mounted frame 21 are the shafts 26 and 27. On shaft 26 are mounted the idler Wheels 28 carrying belts 29. Mounted on shaft 27 are the idler wheels 30 carrying the belts 31. The upper portions of the belts 29 and 30 are supported upon a table 32 also carried by frame A. The lower portion of the belts pass between rollers 33 and 34 supported by frame A.

At the forward end of the table 32, and frame A, I provide cross shafts 35 and 36. Upon shaft 35 are mounted the drive wheels 37, and upon shaft 36 are mounted the drive wheels 38. Wheels 37 carry the forward end of belts 29, while wheels 38 carry the forward ends of belts 31.

Any suitable means for driving the shafts 35 and 36 may be provided. In the illustration given, I provide a drive motor 39 which drives through reduction gears 40, a sprocket-equipped shaft 41, and by means of shaft 42, the sprocket-equipped shaft 43. Shaft 43 is connected by a clutch (not shown) for driving the shaft 44 which engages a sprocket 45 on shaft 35 and the chain 46 which engages the sprocket 47 of shaft 36.

The clutch is operated by a solenoid switch 48, which in turn is actuated through the electric cable 49 by a counter device 56. The counter device 59 is actuated by the shaft 51 of the cutter 19, and is designed after a predetermined number of revolutions of the shaft to open and close the solenoid circuit. Since the counter and solenoid clutch structure are well known in the art, a detailed description herein is not believed to be necessary.

Operation In the operation of the structure, a paper web or other web provided with a coating such as sandpaper, etc. is fed as illustrated in Fig. 1 forwardly over the roller 14 and there slitted by the rotary knives 15 to form the web portions 11a. The web portions 11a are further severed by the rotary knife 19 to form separate sheets 11b. The sheets 11b tend to fall in a random fashion, but by adjusting the height of the conveyor portion therebelow and carried by the pivotally-mounted frame member 21, it is found that the distance between the knife and the conveyor can be adjusted to cause each particular sheet to fall in the proper or desired position upon the stack therebelow. It is found that some coated sheets tend to curl in one direction, and it is sometimes desired to have the sheet form with the curled edges extending upwardly and sometimes with the curled edges pointing downwardly. By rotating shaft 25 and raising or lowering the rack bar 22, the conveyor portion below the cutter can be so adjusted in height as to cause each sheet to fall with the desired side facing in the desired direction.

The sheets continue to fall upon the stack below until a desired number, say, for example, 100 sheets, have fallen onto the stack, and then the counter device 50 closes a contact for the actuation of solenoid 48. The solenoid 48 operates the clutch on shaft 43 to rotate shafts 35 and 36. The drive wheels 37 and 38 then advance belts 29 and 31 a short distance so as to separate the stacks longitudinally and then the clutch is released. This operation is kept up so as to advance the stacks in spaced relation, as shown more clearly in Fig. 4.

A problem is presented with respect to the closely-an ranged stacks of sheets 11b, in that the edges tend to overlap, as illustrated in Fig. 5. When sandpaper is being separated, it is found that the abrasive in the overlapping portion tends to engage and to make it diificult to separate the stacks. I found that by separating the drive wheels 37 a greater distance than the driven wheels 28, and further by spacing apart the drive wheels 38 a greater distance than the idler wheels 30, the diverging of the belts 29 and 31 is efiective in separating the stacks of sheets. The intermittent advancing of the stacks tends to vibrate the sheets slightly, and the stopping and starting is efiective together with the diverging of the belts for moving the stacks laterally, as illustrated in Fig. 6. The separated stacks may now be grasped by operators so that they may be readily placed within the packages for shipment.

The control mechanism for separating the solenoid clutch 48 may be located at any desired point in the structure. I have found it desirable, however, to utilize the counter device 50 which is already needed to provide an indication of the number of sheets severed, for actuating the switch device 52 for closing the solenoid circuit.

While in the foregoing specification, I have set forth specific structure in considerable detail for the purpose of illustrating embodiments of the invention, it will be understood that such details of structure may be varied widely by those skilled in the art without departing from the spirit of my invention.

I claim:

1. In a sheet forming and stacking device having a slitting means and a cross-cutting means for forming an elongated web into a plurality of sheets, the improvement which comprises a conveyor to receive the sheets from the cross-cutting means, said conveyor having a feed end portion positioned vertically beneath said crosscutting means, a pivotally-mounted frame supporting said feed end portion, the pivot axis of said frame being aligned with but laterally oifset from said cross-cutting means, and means for adjusting the inclination of said frame about said pivot axis and thereby the height of said feed end portion With respect to said cross-cutting means, whereby the sheets falling onto said feed end portion are received to face in a single direction.

2. In a sheet forming and satcking device having a slitting means and a cross-cutting means for forming an elongated web into a plurality of sheets, the improvement comprising a conveyor to receive the sheets from 'the cross-cutting means, the conveyor having a feed end portion positioned vertically beneath said cross-cutting means,

a pivotally-mounted frame supporting the feed end portion of said conveyor, the pivot axis of said frame being aligned with but laterally offset from said cross-cutting means, means for adjusting the inclination of said frame about said pivot axis and thereby the heighth of the feed end portion of said conveyor with respect tosaid crosscutting means, whereby the sheets falling onto the feed end portion of said conveyor are received to face'in a single direction, said conveyor comprising a plurality of endless belts supported in adjacent relation in substantially the same plane at the feed end portion of said conveyor and in diverging relation at the other end thereof while remaining in substantially the same plane, whereby the uniformly aligned sheets in said stacks can be separated Without disturbing the alignment of said sheets even though the sheets in adjacent stacks are interleaved.

References Cited in the file of this patent UNITED STATES PATENTS 376,025 Broussier Ian. 3, 1888 846,716 Ashelm Mar. 12, 1907 922,918 Langston May 25, 1909 1,301,964 Overbury Apr. 29, 1919 1,380,710 Goben June 7, 1921 1,567,706 Cameron et al Dec.'29, 1925 1,569,032 Reichel Jan. 12, 1926 1,722,559 Colbert et a1 July 30, 1929 1,826,889 Koch Oct. 13, 1931 1,938,110 Neutelings Dec. 5, 1933 1,957,559 Thickens May 8, 1934 2,134,310 McGrath Oct. 25, 1938 2,545,667 Malnati Mar. 20, 1951 

